M. Bakrutheen

Effect of antioxidants on critical properties of natural esters for liquid insulations

This work is focused towards identifying alternate insulating medium for replacing the mineral oil. With this aim, investigations are carried out with natural esters based vegetable oils which are considered as environmental friendly and biodegradable products. This work also extends to analyze the properties of vegetable oils with the antioxidants for enhanced insulating medium of transformer applications. The natural esters based vegetable oils such as honge oil, neem oil, mustard oil, punna oil and castor oil are considered as samples for the investigations. The butylated hydroxy toluene, butyalted hydroxy anisole and gallic acid are picked as the investigating antioxidants. Different particle volume fraction ranges from 0% to 1% of antioxidants are included for studying the performance of natural esters. The performances of natural esters without and with antioxidants are examined according to the international standards. From the investigation results, it is found that the natural esters based vegetable oils without and with antioxidants have the potential to replace the mineral oil as the insulating medium in the transformers. The mathematical functions for properties are developed based on the results obtained for various concentration of antioxidant. These functions are used to estimate the intermediate values of properties for different antioxidant concentrations.

Analysis of vegetable liquid insulating medium for applications in high voltage transformers

In high voltage transformers, the liquid insulations are used as the insulating medium as well as cooling medium. For the past several decades, the mineral based transformer oil is used traditionally for the purpose of liquid insulations. In the environmental aspect, there are several disadvantages in the mineral oil even though it has better insulating properties. By considering the environmental aspect and insulating properties, the researchers tend to find the alternate insulating fluids for the high voltage applications. In this work, the natural ester based vegetable oils are investigated to analyze the suitability of it as better insulating medium. The different vegetable oils such as mustard oil, olive oil, gingelly oil, groundnut oil, sunflower oil, palm olein oil and rice bran oil are investigated with the measurement of properties like breakdown voltage, flash point, fire point and viscosity. Further analysis are made with the comparison of properties, the fatty acid content and cost of vegetable oils. From the investigations, it is shown that the natural ester based vegetable oils have the potential to replace the traditional mineral oil.

Performance of natural high oleic ester based blended oil insulation for transformer

Energy requirements of whole world have been dominated by petroleum products for many years in various application fields. In order to find the potential replacement for conventional mineral oil, natural based ester oil is proposed as alternative liquid insulation with the consideration of eco-friendly nature among ester oil, the oil with oleic acid content has oxidation resistance and low viscous nature. In this work blending of mineral and high oleic ester oil with different ratio were carried out to study the typical characteristics of blended liquid as liquid insulation. Olive oil and rapeseed oil which has high oleic acid content are selected for investigation. Investigation properties like viscosity, breakdown voltage, flash point, acidity, moisture content and moisture saturation rate were measured for different combinations as per international standards (IEC and ASTM). Investigation reveals that both olive and rapeseed based blended oil show better characteristics, among that olive based blended oil have superior properties than that of rapeseed oil.

Investigation of vegetable oil blended with antioxidant

The Energy requirements of the total world have been subjugated by petroleum products for centuries in many application fields including transportation, household, and electricity. Traditionally, mineral oil is used as insulating fluids in transformer. Mineral oil in transformer can be potentially hazardous to the environment when there is any accident during its working time. In order to conquer these facts, vegetable oil is projected as substitute for transformer oil because it is more environments friendly. In this work, investigation of various parameters like breakdown voltage, viscosity, water content, interfacial tension, acidity, flash point and fire point of different vegetable oils like sunflower oil, rice bran oil, soybean oil and corn oil are carried out. This work is extended to analyze blending of various proportions of antioxidant to different vegetable oils. The different parameters like breakdown voltage, viscosity, water content, interfacial tension, acidity, flash point and fire point are measured. From the investigations, the more suitable combination for transformer insulation is figured out, which has properties similar or superior to mineral oil.

Investigations on critical properties of blended edible natural esters based insulating oil

Present growing demand for renewable, environment friendly and biodegradable insulating liquids for high voltage applications lead to find the potential alternative to petroleum based mineral oil as insulating medium. In this paper, an attempt is made to find the alternative insulating fluid with better insulating characteristics and eco friendly nature. This work reports on the experimental investigations on the edible natural esters and their blended combinations. The investigations are carried out for finding the critical properties such as breakdown voltage, flash point, fire point and viscosity according to international standards. Olive oil, rice bran oil and soya bean oil based edible natural esters are taken for investigations in individual form and in blended combinations of them. Blended combinations are taken in the range from 0% to 100%. From the experiments, it is found that the edible natural esters have the potential to replace the traditional mineral oil. The edible natural esters and the blended combinations of the edible natural esters have the better properties than the mineral oil. Their eco friendly nature, biodegradability and better insulating properties of edible natural esters pave the way for new insulating medium for high voltage applications.

Investigation on the Properties of Natural Esters Blended with Mineral Oil and Pyrolysis Oil as Liquid Insulation for High Voltage Transformers

For the several decades, petroleum-derived mineral oil has been used as liquid insulation due to its better operating properties, low cost and availability. Many research works have been performed over the years to find the potential replacement of traditional mineral oil to overcome its disadvantages such as poor biodegradability, environmental issues and scarcity of availability in future. In these aspects, various vegetable oil-based natural esters are investigated by the researchers throughout the world. With the objective of developing functional efficient liquid insulation for high-voltage transformers, investigation is carried out with natural esters (sunflower oil, rice bran oil, corn oil and olive oil), blended with traditional mineral oil and biomass-based pyrolysis oil. In this work, for ensuring the characteristics of investigating liquid insulation, properties such as breakdown voltage, flash point and viscosity are measured according to international standards. From the investigations, it is found that the natural esters and blended oil samples have the properties as nearer to standard values for liquid insulations used in high-voltage transformers and have the ability to replace traditional mineral oil as alternate liquid insulation.

A statistical study on the AC breakdown voltage of corn oil and mineral oil for liquid insulation

In recent years, insulation designers have been emphasized many researches on natural ester oils to replace mineral oil because of its high biodegradability, better dielectric characteristics, more resource of availability and etc. This work aims to investigate the corn oil (CO) as alternate liquid insulation to mineral oil (MO). In order to ensure the ability of natural ester as potential replacement for liquid insulation, statistical analysis of AC breakdown strength is conducted apart from measuring the other oil properties such as density, viscosity, flash point, fire point, color, moisture content and acidity. Statistical analysis of breakdown voltage on corn oil is carried out with two parametric distributions (Normal and Weibull distribution). The probability of failure with respect to the breakdown voltage on corn oil and at risk levels of 1%, 5%, 10%, 25% and 50% probability are estimated to ensure the withstand capacity of corn oil under various stress conditions. For reference purpose, mineral oil is also investigated in this work. From the statistical investigation result, it is found that the corn oil has the suitable and better breakdown characteristics than the mineral oil. Hence the corn oil has the potential to replace traditional mineral oil in high voltage transformer.